Sampling device



NOV. 28, 1944. 5' SWEAR|NGEN 2,363,625

SAMPLING DEVICE Filed March 6, 1942 By YW@ Patented Nov. 28,'1944 l pApplication March 6, 1942', Serial? No.1433;68\7f` l loma-4212).

n n n l1- Claims; This invention relates toa sampling apparatus and hasVfor its general object the provision of..

a device for taking. a'true sample from a flowstream of a gaseousandliquid mixture. It is well "known that anaccu'rate sample of a lbwingstream of a gaseous mixturegmay betaken by simply` tapping` theconduitfand withdrawing the sample. of gasand liquid a true sample ofthemixture in properproportioncannot in general l.be se cured' in thiswa asthe ordinarily unpredictable character ofthekinetics of the now inthevicin-` `ity ofthe entrancetothe.sample-colleetingdefv viceirnay causelsome of :the liquid droplets", be-` cau-se offtheir density,"tokbethrown4 clear` ofthe However, in the case oi. a mixture of "turbulence"andi placed even ya lshort Adis-- collect a true sampleb'ecause som-eof the" liquid` win again `nave reach-ed the walleor the tubehecarriedalong` fthe' wa-Il aslfaA liquidi layeri as `previously:`indicated Awhere .the sampling "tipi have 'access to it `11o-'collectthe `aliquot n partof'iti N "It-isfthereiore an object`orthis'i"nventlor11itu provide-y an* apparatus wwherebya: true samplemay betaikenFfronr ain-owing" stream of-a gas and' liquidniix'turewithout Athe sample being" affected l lig/"eitherthe4collectiorroi,liluidfanorrfthe walls i of the conduit orthehighvelocity and "indetersample-collector thereby leaving thesample del` ilcient 'in liquid, or an excess of liquid `may bev throwninto the samplecollector asif .bombarded bythe droplets. or `an`excessive prGpOrtion`of.`

liquid may lbe collected bythe`` sarnple collector `lected on `the wallof" the conduitandfhaving;

'literally `pours into the sample eolleetorn` by Virtue of `aportionoftl'ie liquid. hailingA coli bee'ncarried'bylthe force Iofthestream .of `gas and l entiained lifquidto the. `point of SamplingWnere.`

"A sommen tb n this amenity is. by.` means off the wellfr-lg'nownsharpfedged sample tipinserted n into the flowing `stream `of mixture.whereinthee openinginto the sample tip Afaces the streamland: thelinear velocity'of the `stream enteringthe. sampling, tip is thesame. asthatprevailingxin.;

themain stream at thatjpoint. y

"However, this method is successi ul only; if;` all `ef` theliquid isintimatelyand, uniformly dispersed...`

throughout "the gaseousv phase Vso that the comw-A positionof the streamatfthe .point .ot sampling is the same as that ofthe average` of thewhole-` stream. jIt hasbeenfound in theowfof. such."

a"mixt`u`re of gas;and liquid that thedioplets of liquid each `atlrandommaycollide `with the walls of theconduit and stick,thereby forming alayer offliquidon the, wall of thenconduit which.

is in` general carriedalong by Vtheforce'of the: i main strearn of gas.ButUthisM-gaswith its 12e-N maining suspension of liquid-is nowdeficient inv liquid` and a sample df it would not `tet a ...me

` flfhedevice illustratediinthedrawing issuch--l sample ofthe compositestream.` It, .has beenl proposed that a means be provided iorcausing u aviolent turbulence i'njthefowing .stream in order to redisperse theconsolidated liquid phase but .this `means introducesseveral'difticulties.. To i begin with, the complete. dispersion oi the,liquid phase isfvery diicult. Also thecharacter olf` the turbulenceisindenite and a `sampling tip` cannot be satisfactorily operatednearthe point pling"'tip; yAnother; object of. thisinventionA Vis` to@pro-` vide a sampling 'apparatus `which willnot' constitute aconstriction -in the 'conduit when the sampler isjnoti'nuse. i

Still another" object of this. invention is `to provide "a samplingapparatus which will `accurately"sampleajstreaniv of gas andlil'iuifdlii'owingl` minette character?of the flow ladiacent theA sam'-`irr theisam'e-` wherein the liquid 'is not dispersed but *is 'flowingalong4 the, bottoni orfon the wallsjoftheconduit.. n n

"stili anqtner- `object `of ifinis, ,invention isffto: provide a'sampling' apparatus. which will' accuratelySample-a comminglfed stream.oi gas and li'quidoontaining a high. percentage of liquid..`

A. `Still `another object of. this invention. is to provide' asamplingapparlatus which will dispersev any separated` 'liquid vwith apressure,

Qthervobiects advantages of this inven- Y tion willfbecome apparentfronntlie` followingv description taken` in connectionfwithl theaccompanying drawing` whereinisset 'forthone embodiment thereof;`

"Inithe drawing; f A Fig. 1" shows a "longitudinal cross section.

t through a samplings device construetedinaccordam?Witlilthisinventien"n .l

"Eiggfz" shows ajtransverse crosslsect'ibnthrough thefsaxne ',clevicehtaken along,the. .line 2f-2. nt

as would be. "intendedlfor use 'by way of. exam- `pleforia. flow oi anatural- Ldi'stillate gas. from a so-"calleddi'stillate or"condensate;gas..well; It

will be appreciated, of courselthat they device: iis.`

not liinitedxto 'suchujsefbut that such use is re,- ferredjto merely "by`way "of example.v4 In. such. al

l gaseousaxidl liquid mixture-a mixture. `et hy..n drocarbon gases comesfrom the `well having enportion of the conduit by means of the usualsampling tube would not produce a sample having the true proportions ofgaseous and liquid components.

Referring now more particularly to thedrawing, a device is providedwhich consists of an inlet fitting I threaded at 2 so that it may be sevcured to a ow line and having its opposite' end welded at 3 to a body4that extends at substani tially `right angles to the tting I. The body 4isprovided witha bore 5 having a restriction 6 therein and having alateral opening l which communicates with the fitting| and a secondlateral opening 9 to which is welded tting 9 as indicatedwby the numeralI0. The opening I communicates `with a chamber II in this body, thischamber being closely adjacent the restricted boreportion 6A and theopening 8 communicates with another chamber I2 which is separated fromthe Lchamber II by a reduced threaded .zone I3 which acts as a seal.Theend portion of the body, 4 adjacent the chamber I2 is interiorlythreaded at. I4 to receive the stuiiing box I 5 having lpacking I6therein compressed by a gland I'I andgland nut I8. The packing I6 formsa seal about the shaft I9 of an orice forming member "r 'that has atapering endv portion 2I adapted to cooperate with the tapered entrance22 of the restricting z'one 6 so as to provide an annular orificethrough which the flow from the fitting I must pass in order to 'enterthe ow bore 5 of the iittingr4. This throttling4 member 20 ishollowlasshownat 23 and isthreaded at 24 intermediate its Aends forengagement with the threads I3" so that upon rotation of the shaft I9the throttling member 2I will be moved.V toward and away'from thetapered zone 22 to restrict the flow ofthe mixtureI entering'the deviceto a greater or less extent as desired. The hollow interior 23 opensadjacent the annular nozzle as illustrated so lthat the owof mixturethrough this annular nozzle will cause a suction through the hollowIinterior 23 by virtue of the jetting action of the' above mentionedstream .of mixture as it enters and passes through the constrictionorthroat 6. The opposite end of this hollow interior is pro-- vided`with lateral openings 25 into the chamber I2 so that ow through theannularV nozzle will tend to cause iiow from the iitting 9 through thechamber I2 and out .through the hollow interior 23.` i q Theshaft VI9may be adjusted in any suitable manner such as by rotation of the handwheel 26. The free end of the body member 4 is provided with aroundededge 21 and has welded thereabout as shownat -28 a short heavy member 29forming an Aannular housing about thefend portion of the body il.v Theopposite end of this annular housing is vwelded at 30 to a fitting 3l,the adjacentv end of which is spaced slightly from the end 2l of thebody 4 as shown at 32. The interior of this annular housing 29 isconnected by means of anelbow 33 weldedthereto at 34 and a nipple 35welded to the elbow'33 at 36 to the elbow 9.

The nipple 35 is welded at 3'I .to the elbow 9. It will be seen that bythis construction any iiow through the inlet tting I and the annularorince provided by the exterior surface of the member 2I and the taperedportion 22 of the body 4 will not only produce a iiow of this fluidthrough the interior of the body IIr but will cause a suction throughthe hollow space 23, the openings 25, the chamber I2, the elbows 9 and33 and the nipple 35 and will cause iiow to take place from the interiorof the body 4 at the end 21 through the annular opening between said endand the end of the fitting 3l which flow will again be mixed with theowing stream at the annular jet. The annular opening just referred tomust be of such shape and dimensions as to cause the' flow into it to beat an accelerated rate over lthat prevailing in ythe adjoining mainstream so that the pressure rat the entrance to this annular opening isreduced and the liquid flowing toward it.on the wall 5 will be drawn in.

The fitting 3I' is provided with av lateral opening 38 to which isWelded at 39 a short nipple 40 having a' nut 45 through which isextended a sampling'tube 42 fitted with a shoulder 4I and having asampling nozzle 43 thereon located sub-1r stantially in the same planeas the annular opening 32 and directed upstream. This sampling tube 42may be controlled in any suitable manner such as by any cutoff valve 44.1

' In operation, flow will take place from the distillate well or othersource of gas and liquid mix` -tureiin through the tting I to thechamber II and thence through the annular orifice between theend of thethrottling member 2| and thetapered surface 22 through the throat 6.This flow of the mixture will be quite turbulent at this point withinthe throat 6 and will cause it to' .take up in a mist or Vapor form andto disperse and entrain in the stream of ow substantially all oftheliquid which was theretofore more or .less separated and flowing alongthe walls or floor 'of the conduit. The sampling tube 43, however,cannot for the reasons above set forth be placed in this turbulent zonebut must be placed a substantial distance therefrom as illustrated toallow a calming section. vIt has been found, however, that in thisdistance an accumulation of liquid on the walls of the conduit againappears in substantial quantities and it becomes necessary in order toget a. true sample to take care of this subsequent accumulation ofliquid. Moreover it has also been lfound that complete dis` persion ofvthe liquid into the gas is quite difficult by means ofa throttlingdevice in the stream, and any liquid not atomized by the action of theconstriction formed by the exterior surface of the member 2I and thetapered portion 22 of the body 4 or by-the action of the throat 6, willappear on the walls of the bore 5 of the body 4.

A.As above explained, the iiow of the mixture through the annular oricecauses a suction within the hollow portion 23 of the throttling memberand this suction tends to cause ow from the annular'housing 29 throughthe conduit that is provided by the elbows 9 and 33 and the nipple` 35into the chamber I2 through the openings 25 and out throughthe hollowportion 23 into the stream `of flow. Due to this suction and flow,

any liquid lwhich collects uponthe` walls of the tion referred to andwill be carried throughthe,

. acca-eas l `conduit formed by' the `elbows 19v and `35i` and; the:

nipple 35` back: `around and cause to` v`join the` stream-df now. atuthe.oricev where it is 1mb-f `jee'ted `to violent l turbulence in; thetapered `zone immediatelyprecedinglthroat 6,"as well `asin throat 6i.and Ilbeyondxwhere `the `high velocity stream emerging vfrom 1saidthroat impinges upon theslower.movingstreamlin the bore liotbodyfd.

` Thus `no liquid which is not` dispersed `in `the gas isi permitted toipass the (point `at which the end of the sampling tube 43 islocated andfrom also be made `if :desned' whereby the* sampling:

tube, may be withdrawn whennotin use orl turnedl N insuch amanner: thaterosion of thesampling nozzlelmay be reduced to a minimum. `An ani nulartype of nozzle has `been described in the jet and mixing part oftheapparatus but any similarmeanswhich accomplishes `the dispersion whichthe sample `istalren. However, since `this condensate'is passed backinto the main stream i ofilow itis not lost but is againmixed with the.

Stream" offiiow. .Conditions will belmaintained such that liquid `willmotaccumulate in.` this re-l circulation system andfsince liquidisnotpermittedto accumulate, therewill be the same pro-- portion of gas: andliquid: passing into `thelfitting 3l and the sampling tube43 as thatwhich `enters through the iittingyl...I H i i 4'In order to createsuchconditions, it isf neces--` `saryto setup the deviceandbegin takingsamples withthe needlevalve wide open and then. gradually closing `the.needle` valve while continuing to take'sampleslforeach ofya number ofvarious positionsof thefvalve... Asthe valve is `closedit will be `foundthat` the samples taken will show greaterf and greater liquidk contentuntil a maximum is reached after which itwill remain constant as thevalve is closed more. 'The valve should `for most eilicient` operationbe closed just slightly` beyond this `point? wherexthe maximum liquidcontent is found in the` sample, so that if the liquidcontent of` thestreamshould increase walls Vof the `bore Y5.` The. valve should ,not beclosedmuch ,beyond this point however, orit will unduly restrict iiow offluid in the main stream.;

In Iorder todetermine the `proper setting of thelvalve, pressure gauges`46 and vl'l` communi-` i cating with; the chamber Il andthe lbore 5respectivelyil are Aprovided `whereby the @pressure`1` drop through the:needle valve and orifice may be observed. i Then after thetrialfsamplesabove referred. lto: have been .run and ,the `maximum pointdetermined.` the valve `.may bereset tothe proper point 4by varyingitssetting` until the pressuref drop between chamber H and-bore areslightly greater -than when the sample having; themaximum liquid contentwas taken. In order l of the liquid in. `the `gas and the circulationof. the streamentering at the annular' port 32as described may beused.

. In view of thekforegoingit willbe` appreciated that adevice. has: beenprovidedfcapable of carryingjout fully the objects ofsthis invention;

`Having. described myl invention, -I claim:V l

1..I n a sampling device,` a conduit, a sample.

withdrawing device extending into said conduit and having its inletspaced from the walls thereof, means adjacentthe inlet` o-flthe samplewith-d drawing device for collecting all uid on the. wall of saidconduit as theiljuid flows; toward `the inlet of said sample withdrawingdevice, 'and means associated with the conduit for conveyngksaidcollected Iluid `from the. regionofvcollection and introducing the `sameinto and intimately mix-` ing it with a stream of fluidi mixture; owing`slightly-.there will still be enough suction in the housing29 `toremove` all liquid collected on the that the pressure downstream fromthe sampling tip may be observed thepressure gauge 48 corn-" municatingwith interior of fitting 3121s `pro-- vided,` and the pressurein chamberl2 ,may be observed by means ofv the'pres'surelgauge' communicationtherewith. l

It may be noted in connection with this-operation thatl that whichactually happens is `that the reinjection of the liquid through the`hollow portion 23 causes the mixture to be extra rich i in liquidbeginning at the throat 6 and that it true proportions of i all original`mixed iiuid.

through said conduit toward the inlet" of `said sample withdrawingdevice.

. 2. Inansampling device, a conduit, a sample withdrawing deviceextending into "said conduit f andhaving its inlet spaced from the wallsthereof, the walls of said conduit adjacent theinlet of said samplewithdrawing device being interrupted, throughout substantially itsentire cir- ,cumferencegy means for withdrawing" through` saidinterruption in the `walls of the conduit all" iiuid clinging tosaidwalls and approaching the inlet of said sample' withdrawingdeviceand for 'injecting and intimately mixing saidwithdrawn fluid, with astream of fluid mixture `flo-wing through said conduit `toward the inletof said samplewithdrawing device. 1 l l V3. `:In .a` sampling device`for sampling la stream or a mixed fluid one of' the constituents ofwhichl tendsto separate out ofthe mixture and collect onthe walls of aconduit in which conduit throughwhich the stream flows, a samplelwithdrawing device? extending into` said conduit, and means forenriching thefstream of* fluid iiowing toward said samplewithdra'wingdevice by returning thereto in advance of said samn q ple `withdrawingdevice the constituents which separate out of said mixture between suchpoint of addition` and the inlet lto said sample withdraw-` r ing devicewhereby the mixture reaching the let :of the sample withdrawing devicewill have the 4.`In a sampling device, a conduit,"means forming achamber about the exterior. of said conduit at one point, said chamberand the ini terior of said conduit being in communication substantiallythroughout the circumference of the conduit, means for withdrawing fluidfrom may' for example be used depending upon the conditions of`pressure, etc. and different types chamberto mix it with toward saidchamber,

said chamber and injecting it into said conduit n at a position spacedvalong said conduit from said astream of fluid flowing v and means fortaking `and withdrawing a sample from said conduit, said means havingits inlet located adjacent the plane of the openin said chamber.

. 5.` In a sampling device, a` conduitl for the iiow of a stream ofmixediiuids, means for withdrawmg from said conduit at a given region thereofof; assembly may be. employed. Previsioni may it is owing, a

` he constituents of the,` w

between said conduit and any fluid clinging to the walls thereof andcarried toward said given region, means for reinjecting all suchwithdrawn fluid into said conduit to mix it with the stream of iiuidIiowing toward said region, and a sample withdrawing device having itsinlet disposed within said conduit substantially at said region.

6. In a sampling device, means for causing turbulence in a owing streamof gas and liquid to cause the gas to take up the liquid in the streamand form a substantially homogeneous mixture, a sample withdrawingdevice extending into the path of ow of said stream at a substantialdistance downstream from said point of turbulence, and means vfordrawing off liquid separating from said stream between said point ofturbulence and the location of the sample withdrawing device andreturning it tol said stream at the point of turbulence. Y

7. 'Ina sampling device, a conduit, an orifice in said conduit forcausing turbulence in a stream of 'fluid mixture yiowing through saidconduit, a sample withdrawing device extending into the path of flow ofsaid stream a substantial distance downstream from said orice, and meansfor drawing off from said conduit at a position substantially in thesame region as said sample withdrawing device any constituents of saidmixture which may separate therefrom .between said orifice and saidsample withdrawing device and for returning the constituents sowithdrawn to said stream of uid mixture prior to its einer-'- gence fromsaid orifice.

8. In a sampling device, a conduit, an orifice in said conduit forcausing turbulence in a stream of fluid mixture flowing through saidconduit, a sample withdrawing device extending into the path of iiow ofsaid stream at a substantial` distance downstream from said. orifice,means communicating with said conduit at a point substantially in thesame region as said sample withdrawing device for drawing off anyconstituent separating from said stream between said orice and thelocation of said sample withdrawing device and carried toward the latterby the stream, an injector, and means for conducting constituentswithdrawn from the conduit to said injector for reinjecting saidseparated constituents into the flowing stream of fluid mixture as itenters said orifice.

9. In,a sampling device,'a conduit, an orifice inr said conduit, ahollow needle valve adjustably a position substantially in the sameregion as said sample withdrawing means any constituents which may haveseparated out of a uid mixture passing through said conduit, and meansfor conducting such separated constituents to the in-V teriol` of saidhollow'needle valve 'whereby the jetting action of the fluid iiowingabout the outside of said hollow needle valve into said orifice willserve to inject such separated constituents from the interior' of saidhollow needle Valve into said orifice. l

10. Ina sampling device, aconduit, an orifice, in said conduit, anannular needle valve located adjacent the entrance to said orifice forforming with said orifice an annular jet of uid flowing i through saidconduit into said orifice, a shaft carrying said needle valve,threadedly connected with a portion of said conduit, and projecting tothe exterior of said conduit, a hand wheel on said shaft exteriorly ofsaid conduit whereby said shaft may be rotated to adjust the position ofsaid needle valve, said needle valve being hollow for a portion of thedistance from the end thereof adjacent said orifice, means forming anannular chamber about said conduit at a position f spaced downstreamfrom said orifice, said chamber :being in communication with theinterior of said conduit substantially throughout its circumference,means connecting the interior of said chamber with the interior of saidneedlevalve whereby the jetting action of fluid flowing through saidconduit and about said needle valve into saidv orifice will cause fluidto be withdrawn from the conduit into said chamber and reinjected' intothe stream of fluid through the interior of said needle valve, and asample with' flow of a stream of fluids, an orifice in said con.l

f duit, means for jetting said stream of uid flowmounted in the entranceto said orice for causy ing avariable annular jet of fluidflowingthrough said conduit and entering said orifice, a samplewithdrawing device extending into said conduit a substantial distancedownstream from said orifice, means for withdrawing Ifrom said conduitat ing through vsaid conduit and directing it into said orifice, asample withdrawing device extending into said conduit a substantialdistance downstream from said orifice, means for withdrawing from saidconduit at a positie-n substantially in the vsame region as said samplewithdrawing means any constituents which may have separated out of `afluid mixture passing through said conduit, and means for conductingsuch separated constituents `to said jet of fluid entering said orice,whereby the action of said jet of fluid iiowing into said orifice willserve'to inject such separated constituents into said orice with saidjet.

JUDSON S. SWEARINGEN.

